COLORED INTERFERENCE PIGMENTS, A METHOD FOR PREPARING THE SAME

Abstract

"COLORED INTERFERENCE PIGMENTS, A METHOD FOR PREPARING THE SAME" Colored interference pigments having metallic luster comprising, on the surface of a thin platelet-like metal substrate a layer of an anti-corrosive treatment in a non-aqueous system, and, thereon an intermediate binder layer comprising hydrated tin oxide (first layer); and thereon, a hydrated iron oxide layer (second layer), exhibiting a reddish color and improved adhesion and denseness of the hydrated iron oxide layer, a process for producing same and their use.

Full Text

[Title of the Document] Specification
[Title of the Invention] The interference colored
pigments having metallic luster, the preparing method of the
same, and use of the same
[Technical Field]
[0001]
The present invention relates to novel colored
interference pigments having metallic luster, the preparing
method of the same, and use of the same.
[Background Art]
[0002]
Highly anti-corrosive thin platelet-like metal pigments
having high anti-corrosive and good dispersibility without
damaging the original surface smoothness of thin platelet-like
metal substrate such as aluminum flake etc. are well known (for
example, patent document 1. The corrosion resistance for
highly anti-corrosive thin platelet-like metal substrate
pigments is achieved in that after treating the surface of thin
platelet-like metal substrate with phosphoric acid compounds
and/or boric acid compounds (the first layer) in non-aqueous
system, thereafter a hydrated metal oxide is coated thereon (the
second layer) by sol-gel method in non-aqueous system. Further,
colored interference pigments having metallic luster are
obtained by coating one or more hydrated metal oxide layers (the
third layer or more) onto the outer layer of highly anti-corrosive
thin platelet-like metal pigments used as a base by wet process
method in aqueous system (paragraph [0034] of patent document
1).
However, when a hydrated iron oxide is coated directly
onto such "highly anti-corrosive thin platelet-like metal
pigments" as the base for aiming at a reddish color by just applying
the conventional wet process method, the denseness of the

hydrated iron oxide layer is not sufficient, and therefore it
is not possible to achive colored interference pigments having
metallic luster with a reddish color having high luster, high
coloration, strong and improved interference color and high
[0003]
Further, patent document 2 discloses luster pigments based
on multiplycoated platelet like metallic substrates having color
flop with one layer packet comprising, (A) a first layer having
lower refractive index (not greater than 1.8), (B) a second
selectively absorbing layer having high refractive index (not
less than 2.0), and if desired, additionally (C) a third layer
different than the layer (B) underneath. The formation of
multiply layer by combining the first layer (A) having lower
refractive index in said luster pigments with the outer layer
(B) having high refractive index, can increase the reflection
at the multi-layer boundary and improve the interference color
(non-patent document 1, patent document 3, patent document 4,
and patent document 5). There is description of aluminium oxide
or silicon dioxide as an example of the first layer (A), and
is also descriptionof high refractive index materials consisting
of iron (III) oxide, chromium (III) oxide, titanium (III) oxide,
etc. for the second layer (B). Further, as the coating method,
the CVD process and the process by wet-chemical hydrolysis of
an organic metal compound in an organic solvent system are
described; however, there is no description on the reaction in
an aqueous system which can be easily performed (herein defined
as "wet-process method") , and multiply alternate coated layers
containing a selectively absorbing layer were formed directly
on thin platelet-like metal particles without an intermediate
binder layer, to generate the color by interference. The CVD
process is not expected to achieve the homogeneity of the coating

compared with a wet-process method.
[0004]
Patent document 6 discloses multi-layer coated pigments
based on thin platelet-like metal produced by coating the metal
pigments with the amorphous glassy layer consisting of SiO, B2O3
and/or phosphate, or mixtures thereof . However, when aluminum,
which can be easily oxidized, is used as thin platelet-like
metal substrate, hydrogen is easily generated since the coating
process is the direct reaction in aqueous system, and thereby
the smoothness of the metal surface will be damaged, resulting
in irregular reflection from the boundary between the metal and
the "amorphous glassy" layer or losing metallic luster. Thus
it is difficult to achieve the desired coloration with the
lustrous interference color. Moreover, the generation of
hydrogen may cause a potential hazard in practical applications.
[0005]
For example, patent document 7 discloses silica coated
aluminum pigment which exhibits corrosion resistance forming
the silica layer on the surface of aluminum pigment with
silica-containing compound. The layer formed is a single layer
containing phosphorous in the silica coated layer (described
in paragraph [002] ) ; however, there is no description concerning
the interference color having metallic luster with a reddish
color by coating hydrated iron oxide on the outer layer.
[0006]
Patent Document 1: JP, A, 2003-41150
Patent Document 2: JP, A, 08-209024
Patent Document 3: JP, A, 03-120351
Patent Document 4: JP, A, 06-93206
Patent Document 5: JP, A, 07-246366
Patent Document 6: JP, A, 2002-522618
Patent Document 7: JP, A, 2002-88274

Non-patent Document: YamadaK. , "Knowledge in Optics", published
by Tokyo Denki Daigaku Press, 1st version, pp323 to 331 (in
Japanese).
[Disclosure of the Invention]
[Problems to be solved by the Invention]
[0007]
Accordingly, an object of the present invention is to
provide colored interference pigments having metallic luster 11
with a reddish color in which the adhesion and denseness of 1
hydrated iron oxide coated layer formed on the outer layer of
a thin platelet-like metal substrate having a layer of an
anti-corrosive treatment in a non-aqueous system is improved
to achieve high luster and high coloration (chromaticity).
[Means for Solving the Problems]
[0008]
In order to solve the above problems; the inventors of
the present invention have carried out eager investigations and
found that coating a special intermediate binder layer right
on the surface of the thin platelet-like metal substrate having
a layer of an anti-corrosive treatment in a non-aqueous system
is able to surprisingly improve the adhesion and denseness of
the hydrated iron oxide coated layer formed further outside
thereof so that a reddish color with high luster and high
coloration (chromaticity) is achieved, whereupon the present
invention has been accomplished.
Thus, the present invention relates to colored
interference pigments having metallic luster comprising, on the
surface of a thin platelet-like metal substrate, a layer of an
anti-corrosive treatment in a non-aqueous system, and, thereon
(1) an intermediate binder layer comprising hydrated tin oxide
(firs layer); and thereon,
(2) a hydrated iron oxide layer (second layer).

[0009]
The present invention also relates to the above-mentioned
colored interference pigments having metallic luster, wherein
the layer of an anti-corrosive treatment in a non-aqueous system
is a hydrated metal oxide layer obtained from the following steps:
Treating the surface of the thin platelet-like metal substrate
with phosphoric acids compounds and/or boric acids compounds,
followed by coating one or more hydrated metal oxide layers of
one or more metals selected from the group consisting of silicon,
aluminum, zirconium and titanium by the sol-gel method.
The present invention further relates to the
above-mentioned colored interference pigments having metallic
luster, wherein the metals of the hydrated metal oxide in said
hydrated metal oxide layer are silicon and/or aluminum.
The present invention further relates to the
above-mentioned colored interference pigments having metallic
luster, wherein the metal of the hydrated metal oxide in said
hydrated metal oxide layer is silicon.
[0010]
The present invention further relates to the
above-mentioned colored interference pigments having metallic
luster, wherein said intermediate binder layer (the first layer)
is a layer comprising hydrated tin oxide obtained by the
hydrolysis of a tin salt.
The present invention also relates to the above-mentioned
colored interference pigments having metallic luster, wherein
the amount of hydrated tin oxide in the intermediate binder layer
(the first layer) is not less than the amount which is necessary
to form a monolayer of hydrated tinoxide on the thinplatelet-like
metal substrate having a layer of an anti-corrosive treatment
in a non-aqueous system.
[0011]

The present invention further relates to the
above-mentioned colored interference pigments having metallic
luster, wherein the amount of hydrated tin oxide in the
intermediate binder layer (the first layer) is 0.0008g to 0.3g
as metal oxide (SnO2) per unit surface area (m2) of the thin
platelet - like metal substrate having a layer of an ant i -corrosive
treatment in a non-aqueous system.
The present invention also relates to the above-mentioned
colored interference pigments having metallic luster, wherein
the amount of hydrated iron oxide in the hydrated iron oxide
layer (the second layer) is 0.01g to 1.0g as metal oxide (Fe2O3)
per unit surface area (m2) of the thin platelet-like metal
substrate having a layer of an anti-corrosive treatment in a
non-aqueous system.
[0012]
The present invention further relates to a method for
preparing colored interference pigments having metallic luster,
comprising the following steps:
- Dispersing/suspending thin platelet-like metal
substrate particles having a layer of an anti-corrosive
treatment in a non-aqueous system in water,
- Adding simultaneously an aqueous solution of a tin salt
and a basic aqueous solution to the
dispersion/suspension while keeping the pH value
constant and forming a first layer of a hydrated tin
oxide (an intermediate binder layer) on the surface
of said thin platelet-like metal substrate having a
layer of an anti-corrosive treatment in a non-aqueous
system; and further
- Adding simultaneously an aqueous solution of an iron
(III) salt and a basic aqueous solution while keeping
the pH value constant and forming a hydrated iron oxide

layer (the second layer).
[0013]
The present invention also relates to a composition of
resin/oil and pigment comprising a resin component, and/or an
oil component, and the colored interference pigments having
metallic luster described above.
The present invention also relates to the above-mentioned
composition of resin/oil and pigment comprising additively
further pigments.
[0014]
The present invention also relates to the use of the
composition of resin/oil and pigment in paints, coated films,
painted materials, inks, printed materials, plastics, moldings,
or cosmetics.
The present invention further relates to a painted material
having at least one painted layer comprising the composition
of resin/oil and pigment.
[Advantages of the Invention]
[0015]
The colored interference pigment having metallic luster
of the present invention is one in which thin platelet-like metal
substrate having a layer of an anti-corrosive treatment in a
non-aqueous solution is coated with an intermediate binder layer
consisting of hydrated tin oxide thereon to improve the adhesion
and denseness of hydrated iron oxide layer formed outside thereof
compared with a case having no intermediate binder layer
(hydrated iron oxide layer is directly coated on thin
platelet-like metal substrate having a layer of an anti-corrosive
treatment), so that a reddish color with high luster and high
coloration is achieved. Moreover, since thin platelet-like
metal substrate having a layer of a highly anti-corrosive

treatment is used during coatings, it is able to achieve
homogeneous coatings by utilizing so-called wet-process method
in which the procedure is simple and easy to operate.
[Best Modes for Carrying out the Invention]
[0016]
Hereinafter, the present invention will be explained in
more detail together with the preparing method.
The highly anti-corrosive thin platelet-like metal
substrate used in the present invention has a layer of an
anti-corrosive treatment in a non-aqueous system. The thin
platelet-like metal substrates as the core of the above-mentioned
highly anti-corrosive thin platelet-like metal substrates are
composed of metals and metal alloys.
The thin platelet-like metal substrates used in the
present invention have an average particle diameter of 2 to 100
µm and an average thickness of 0.02 to 5 µm, preferably an
average particle diameter of 5 to 50 µm and an average thickness
of 0.05 to 2µm, and more preferably, they have an average
particle diameter of 5 to 30 µm and an average thickness of 0.1
to 2µm. Specific examples of flakes include aluminum flakes,
titanium flakes, iron flakes, bronze flakes, stainless steel
flakes, aluminum bronze flakes, various aluminum alloy flakes,
various titanium alloy flakes, and others. Preferred flakes
include aluminum flakes, titanium flakes, stainless steel flakes,
bronze flakes, etc; and, even more preferred flakes include
aluminum flakes (for example, supplied by Silver Line Co. Ltd. ,
Showa Aluminum Co. Ltd., Toyo Aluminum Co. Ltd., Asahi-Kasei
Metals Co. Ltd., Eckart-Werke, etc.), titanium flakes, and
stainless steel flakes, etc. of which there is a stable supply
commercially available as the brilliant metallic pigments.
[0017]
Among these, thin platelet-like metal substrates

commercially available in various states may be used, such as
those substrates that have already been suspended in an organic
solvent to prevent the oxidative corrosion caused by the moisture
contained in the air (for example, pigment pastes suspended in
mineral spirit etc.), those substrates that, for the purpose
of leafing or for improving dispersibility, have been treated
with different types of surface treatment agents and have been
suspended in an organic solvent and those substrates on whose
surface an oxidation protection film (passivation film, i.e.
surface oxidized thin-film layer) has been applied beforehand.
Regarding the object of the present invention, its effect is
brought out particularly by metal flakes having high
corrosiveness, as long as the surface is largely free from
oxidation, hence the use thereof is preferred. For example,
those substrates with high corrosiveness such as aluminum flakes
which are available in the market at the state of suspension
in an organic solvent before being handled and those substrates
which have been treated with different surface treatment agents
and have been suspended in an organic solvent are particularly
recommended for use inthepresent invention. It is alsopossible
touse thinplatelet-likemetal substrates and thinplatelet-like
alloy substrates which have been subject beforehand to an
anti-corrosive (passivation) treatment.
[0018]
The metal substrates having a layer of an anti-corrosive
treatment in a non-aqueous system used in the present invention
include, thin platelet-like metal substrates which are treated
on their surface with phosphoric acid compounds and/or boric
acid compounds, and are further coated with one or more hydrated
metal oxide layers of one or more metals selected from the group
consisting of silicon, aluminum, zirconium, and titanium by
sol-gel method such as, for example, described in patent document

1 (JP, A, 2003-41150). Considering their good surface
smoothness, dispersibility and surface inherent metallic luster,
good adhesion of the intermediate binder layer and the hydrated
iron oxide layer formed further outside thereof according to
the present invention, the above-mentioned anti-corrosive thin
platelet-like metal substrates comprising a layer of phosphoric
acid compounds and/or boric acid compounds and one or more
hydrated metal oxides layer of one or more metals selected from
silicon, aluminum etc. by sol-gel method are adopted.
[0019]
Those treatments of highly anti-corrosive thin
platelet-like metal substrates with phosphoric acid compounds
and/or boric acid compounds may be carried out in accordance
with the description in JP, A, 2003-41150.
The metals used for the hydrated metal oxides layer, which
is to be successively formed, may be selected from the group
consisting of silicon, aluminum, zirconium, and titanium.
Among these, silicon and aluminum are preferred due to their
good transparency and low index of refraction. Especially,
silicon is preferred because it is easy to handle. The sol-gel
method (described in JP, A, 2003-41150) among non-aqueous
reactions for coating the second layer of this high
anti-corrosive treatment is preferred to maintain the surface
smoothness.
In the description of the present specification, for
example, thin platelet-like metal treated with phosphoric acid
compounds and/or boric acid compounds combined with further
hydrated metal oxide layer in non-aqueous system described in
JP, A, 2003-41150, is defined as "thin platelet-like metal
substrate having a layer of an anti-corrosive treatment in a
non-aqueous system" , thereon the layer comprising hydrated tin
oxide is coated as "intermediate binder layer" (first layer),

and the hydrated iron oxide layer, which is an outer layer thereof,
is coated as "the second layer." Further, the term "hydrated
oxide" used in "hydrated metal oxide" generally refers to, unless
otherwise stated, "oxides", "hydroxides", "hydrates of oxide" ,
and "hydrated oxides" of metal, and "mixtures thereof" in the
present invention. The term "oxide" in "metal oxide" is also
based on the definition for "hydrated oxide". Moreover, when
representing such "hydrated metal oxide" by chemical formula
(which is described, for example, in an embodiment, etc.), it
is conveniently represented by the form of oxide.
[0020]
Next, the intermediate binder layer (the first layer) for
improving the adhesion and denseness of the second layer will
be described.
The intermediate binder layer, which is the closely
followed outer layer of the above-mentioned highly
anti-corrosive thin platelet-like metal substrate, can be
obtained in the following way. A suitable material for the
intermediate binder layer (the first layer) is hydrated tin
oxide.
The above-mentioned highly anti-corrosive thin
platelet-like metal substrate is dispersed in water while
keeping the temperature at 60 to 90 °C to be easy to control
the homogeneous coated layer, and a tin salt aqueous solution
and a basic aqueous solution are simultaneously added to the
suspension while keeping the pH constant thereby coating the
hydrated tin oxide layer (intermediate binder layer) onto the
highly anti-corrosive metal substrate. The pH is preferably
less than 4.7. And more preferably, the value of pH of 0.5 to
3.0 may be adopted.
[0021]
The amount of hydrated tin oxide in the intermediate binder

layer (the first layer) for thin platelet-like metal substrate
having a layer of an anti-corrosive treatment in a non-aqueous
system needs to be a sufficient amount not to cause the underlying
base (the layer treated in non-aqueous system) to be exposed.
That is, the amount must be over the amount to be necessary to
form a monolayer. The amount of hydrated tin oxide per unit
area (m2) of thin platelet-like metal substrate having the layer
with anti-corrosive treatment in non-aqueous system is
appropriately not less than 0.0008g as metal oxide (SnO2).
Specifically, the amount of hydrated tin oxide used in
the intermediate binder layer (the first layer) needs to be
adjusted appropriately according to the kind, particle size and
particle size distribution of thin platelet-like anti corrosive
metal substrate . Considering the unit surface area of the highly
anti-corrosive metal substrate, of course, the amount is
decreased when the particle size is large, and it is necessary
to increase the amount when the particle size is small.
[0022]
The amount of hydrated tin oxide is adjusted to be within
the possible range in which the sufficient adhesion and the
improvement of denseness of the second layer are achieved and
the hue of the interference color can be controlled; thus the
amount per unit area (m2) of thin platelet-like metal substrate
having a layer of an anti-corrosive treatment in a non-aqueous
system is preferably 0.0008g to 0.3g as metal oxide (SnO2) , more
preferably 0.0009g to 0.2g, and further preferably 0.01g to 0.1g.
For example, when using the highly anti-corrosive substrate
(specific surface area of 3.01 m2/g (described in Table 3 of
JP, A, 2003-41150)) including metal aluminum as thin
platelet-like metal, the suitable amount is 0.001g to 0.06g per
unit area (m2) of the highly anti-corrosive metal substrate.
The aqueous solution of tin salt to be used is water-soluble

tin(II) salt or tin(IV) salt. For example, tin(II) chloride,
tin(IV) chloride, tin(II) sulfate, tin(II) acetate, tin(II)
oxalate etc. are preferred.
[0023]
Hereinafter, the coating of hydrated iron oxide (the second
layer) after forming the above-mentioned intermediate binder
layer will be described. In the present invention, though the
coating of hydrated iron oxide (the second layer) onto the surf ace
of the intermediate binder layer (the first layer) may be
performed through the vapor deposition method or sol-gel method,
it is more preferable to adopt the wet process (see the description
in JP, A, 2003-41150 for the definition) in which, in contrast
to the vapor deposition method and so-gel method, it has no
restrictions on the raw materials and production facilities and
it is easy to achieve the homogeneous coated layer, and it is
easy to operate a simple process with a wide range of applications .
[0024]
A definition of the wet- process method, as used in the
present invention, has been given before, to be more specific,
in an aqueous system, the method consists of (1) in the case
of neutralizing hydrolysis, selecting the desired water-soluble
metal salt (for example, nitrate salt, sulfate salt, chloride,
acetate salt, and further metal acid salt, etc.) and the
prescribed amount of aqueous solution while separately preparing
an alkaline aqueous solution (an acidic aqueous solution in the
case of metal acid salt), dropping these into the suspension
of highly anti-corrosive thin platelet-like metal pigment
which is the base obtained beforehand while maintaining a
predetermined pH to form a hydrolyzed layer on the surface,
thereafter washing, filtering, drying and, if desired,
calcining; and (2) in the case of thermal hydrolysis, adding
the predetermined amount of the desired water-soluble metal salt

to a suspension of highly anti-corrosive thin platelet-like
metal pigment which is the base obtained beforehand and by heating,
forming ahydrolyzed layer and, thereafter, washing, filtering,
drying and, if desired, calcining. Moreover, as a variation
of the method by neutralization hydrolysis (1) , a method using,
instead of the alkaline aqueous solution, urea and acetoamide
producing alkalinity through heating,(the so-called
"homogeneous precipitation method") can also be mentioned.
[0025]
The iron (III) salt to be used may be water-soluble salts
such as chloride, sulfate, and nitrate. After coating the
above-mentioned intermediate binder layer (the first layer),
the iron salt aqueous solution is successively added while
maintaining the pH constant (not higher than 4) using an alkaline
aqueous solution. Specif ic examples of alkaline aqueous solution
used in the present invention include aqueous alkali metal
hydroxide solution such as sodium hydroxide, potassiumhydroxide
etc., aqueous alkali metal carbonate solution such as sodium
carbonate, potassium carbonate etc., aqueous alkali metal
bicarbonate solution such as sodium bicarbonate, potassium
bicarbonate etc. , ammonium carbonate, ammonium bicarbonate or
an aqueous ammonia solution etc. The amount of hydrated ion oxide
is preferably 0.01g to 1.0g as metal oxide (Fe2O3) per unit area
(m2) of thin platelet-like metal substrate having a layer of
an anti-corrosive treatment in a non-aqueous system in order
to achieve a reddish color and to improve its chromaticity
sufficiently. Therefore, the amount may be appropriately
changed depending on the hue and surface smoothness of individual
thin platelet-like metal substrate, and the properties of highly
anti-corrosive metal substrate obtained and treated in
non-aqueous system. The temperature during this coating
process is preferably the same as one during the coating of the

above-mentioned intermediate binder layer (the first layer) in
terms of efficiency. Thus the obtained suspension containing
the colored thin platelet-like interference pigments having
metallic luster with a reddish color are then filtered and washed,
dried, and calcined.
[0026]
The colored interference pigments having metallic luster
with a reddish color obtained according to the present invention,
exhibit a reddish body color with an interference color by coating
with an intermediate binder layer to improve the adhesion and
denseness of the hydrated iron oxide layer (the second layer)
coated thereon.
[0027]
By performing different types of additional surface
treatments, the colored interference pigments having metallic
luster with a reddish color obtained according to the present
invention meet with the quality required for the applications
for which these treatments are used. For example, it is possible
to carry out treatments for light resistance, water resistance
and weather resistance required for applications as automobile
paints (for example, according to JP, A, 63-130673, JP, A,
01-292067, etc.), e.g. treatments for high plane orientation
properties (leafing) required e.g. in the painting and printing
fields (for example, according to JP, A, 2001-106937, JP, A,
11-347084), water-borne treatments for water-borne paints or
inks (for example, according to JP, A, 8-283604), silicon
treatment for improving dispersibility and
hydrogenpolysiloxane treatment for improving hydrophobic and
oleophobic properties for applications in the cosmetics field,
surface treatments for weld-line prevention when used as resin
(forexample, according to JP, A, 03-100068, andJP, A, 03-93862) ,
and different treatments for improving dispersibility.

[0028]
Hereinafter, the use of the colored interference pigments
having metallic luster with a reddish color obtained according
to the present invention will be described.
The colored interference pigment having metallic luster
with a reddish color obtained according to the present invention
may be used in compositions which may additionally include
further pigments, resin components and/or oil components for
various applications such as paints, printing inks, resin
moldings, cosmetics, etc. Specific examples of them will be
described below. Although not specifically mentioned, "the
pigment in the present invention" used in the following examples
indicates "the colored interference pigments having metallic
luster" including the ones prepared by applying the
above-mentioned various treatments.
[0029]
Use for paints
Examples of use in paints are organic solvent-type paints,
NAD (non-aqueous dispersion) paints, water-borne paints,
emulsion paints, colloidal paints and powder coating. The
pigment of the present invention can be mixed in a proportion
of 1 to 100 wt% with respect to the paint resins as solid parts.
A proportion of 1-70 wt% is preferred. A proportion of 1-20
wt% is particularly preferable. For improving the
dispersibility, the surface of the pigments in the present
invention can be treated with silane coupling agents and titanium
coupling agents. Examples of resin components for the paints
in the present invention are acrylate resins, alkyd resins,
unsaturated polyester resins, amino resins, melamine resins,
polyurethane resins, epoxy resins, polyamide resins, phenol
resins, cellulose resins, vinyl resins, silicone resins,
fluorine resins, etc. These resins may be used alone or in

gravure printing, screen printing, ultraviolet cure printing,
relief and lithographic printing. The use of pigments that have
been subject to a high plane orientation treatment for inks
results in improvement of coloration of interference colors on
the printed surface.
[0035]
Use for plastics
In the present invention, when incorporated in plastics,
the pigments can be mixed with the resin, either directly or
after previously forming of pellets, and then incorporating into
various types of molded products by means of extrusion molding,
calender molding, blow molding, etc. As the resin component,
any of polyolef in-based thermoplastic resins and epoxy-based,
polyester-based and polyamide (nylon)-based thermosetting
resins can be used. A small amount of pigments can be sufficient
to effectively produce the color effects of the pigments of the
present invention, e.g., when forming a multi-layered plastic
bottle, the external appearance of the bottle can be made to
apper effectively by incorporating the pigments in the resin
of the outer layer. Especially pigments obtained in the present
invention on which an additional plane orientation treatment
has been performed (as described above) are preferred for the
purpose of improving the coloration. Naturally, it is also
possible to use the pigments in the present invention on which
a weld-line prevention surface treatment (such as encapsulation
etc.) has been performed.
The pigments in the present invention can also be used
in combination with other pigments. Examples of such pigments
include titanium dioxide; calcium carbonate; clay; talc; barium
sulfate; white carbon; chromium oxide; zinc oxide; zinc sulfide;
zinc powder; metal powder pigments; iron black; yellow iron
oxide; red iron oxide; chrome yellow; carbon black; molybdate

which, however, are not intended to limit the present invention.
(Example 1)
Preparation of the colored interference pigment having metallic
luster with a reddish color (Fe2O3/SnO2/ [SiO2/Al(P)])
50 g of thin platelet-like metal substrate having a layer
of an anti-corrosive treatment ([SiO2/Al(P) ] obtained according
to example 4-b in paragraph [0061] of JP, A, 2003-41150, the
specific surface area : 3.01 m2/g) are suspended in 1 liter of
water. The suspension is heated to 75°C under stirring. 100g
of SnCl45H2O solution with a concentration of 2 9g/l are dropped
into the suspension while keeping the pH at 1.8 using 32% by
weight aqueous solution of sodium hydroxide (preparation of the
first layer, "intermediate binder layer"). Thereafter, the pH
is further adjusted to 3.0 using 32wt% sodium hydroxide . Then,
1816g of FeCl3(III) aqueous solution with a concentration of
3 0g/l are dropped until the desired hue of color is reached while
keeping the pH at 3.0 using 32wt% sodium hydroxide (preparation
of the second layer) . From the suspension, the solid parts are
filtered, washed, dried, and calcined at 350°C for 30 minutes,
the colored interference pigments having metallic luster with
a reddish color are obtained. The amount of coated hydrated
tin oxide is 0.0033g as metal oxide (SnO2) per unit surface area
(m2) of thin plate-like metal substrate having a layer of an
anti-corrosive treatment in a non-aqueous system. Also the
obtained colored interference pigment having metallic luster
with a reddish color have the specific surface area of 25.95
m2/g. SEM observation confirms the existence of high dense and
homogeneous coated layer of hydrated iron(III) oxide shown in
Fig. 1. The amount of hydrated iron(III) oxide is about 0.18
g as Fe2O3 per unit area (m2) of thin plate-like metal substrate
having a layer of an anti-corrosive treatment in a non-aqueous
system. Cross section by SEM observation, shown in Fig. 2,

demonstrates clearly the existence of hydrated tin oxide layer
(the intermediate binder layer) having a thickness of about 2 0
nanometers.
Table 1 shows L value, a value, b value, chromaticity C,
and hue angle h. A colored interference pigment having metallic
luster with brilliant reddish color having high chromaticity
is obtained.
[0042]
(Comparative example 1)
Preparation of a colored interference pigment having metallic
luster (Fe2O3/[SiO2/Al(P)])
The pigment is obtained by the same procedures as in example
1 except that the process of preparation of the intermediate
layer from SnCl45H2O is omitted. Only the hue of an orange color
is obtained, while the reddish color is not achieved. SEM
observations reveal the existence of inhomogeneous coated layer
of Fe2O3 with a large amount of non-coated hydrated iron oxide
particles shown in Fig. 1. It's specific surface area is 40.67
m2/g.
[0043]
Evaluation of coloration
1 weight part of the sample obtained as described in Example
1 above is dispersed in 9 weight parts of acryl-modified
nitrocellulose lacquer and coated on a black and white hiding
test paper with an applicator (bar coater #20) . After drying,
the color measurement is performed by using the
goniospectrophotometer GCMS-3 (manufactured by Murakami Color
Research Laboratory). The results of the color measurement is
shown in Table 1.
[0044]
Table 1 Result of color measurement by
goniospectrophotometer and specific surface area (incidence

Where, chromaticity (C) represents the square root of (a*2 +b*2),
and hue angle(h) represents Tan-1 (b*/a*).
[0045]
It is demonstrated by the above results that the colored
interference pigment having metallic luster with a reddish color
obtained by coating with intermediate binder layer (first layer)
consisting of hydrated tin oxide according to example 1 of the
present invention exhibits both high luster and high chromaticity
as shown in Fig. 3, compared to the comparative example.
Comparative example 1 which has no intermediate binder
layer can not achieve the colored interference pigment having
metallic luster with a reddish color having high chromaticity.
Table 1 shows the specific surface areas of example 1 and
comparative example 1. As shown in Table 1, one having the
intermediate binder layer of hydrated tin oxide as the first
layer has a smaller specific surface area and further hydrated
iron oxide coated layer has a high density or exhibits denseness
and therefore shows good adhesion.. Thus, the chromaticity of
reddish color has been increased.
(Example 2)
Preparation of the colored interference pigment having
metallic luster with a reddish color (Fe2O3/SnO2/[SiO2/Al(P)])
100 g of thin platelet-like metal substrate having a layer
of an anti-corrosive treatment ( [SiO2/Al (P) ] obtained according
to example 4-b in paragraph [0061] of JP,A,2003-41150, the

specific surface area: 3.01 m2/g) are suspended in 2 liter of
water. The suspension is heated to 75°C under stirring. 186 ml
of SnCl45H2O solution with a concentration of 50g/l are dropped
into the suspension while keeping the pH at 1.8 using 20% by-
weight aqueous solution of sodium carbonate (preparation of the
first layer, "intermediate binder layer"). Thereafter, the pH
is further adjusted to 3.0 using 20wt% sodium carbonate. Then,
4540g of FeCl3(III) aqueous solution with a concentration of
87.75g/l are dropped until the desired hue of color is reached
while keeping the pH at 3.0 using 20wt% sodium carbonate
(preparation of the second layer). From the suspension, the solid
parts are filtered, washed, dried, and calcined at 350°C for
30 minutes, the colored interference pigments having metallic
luster with a reddish color having hue angle (h) of 32.52 are
obtained. The amount of coated hydrated tin oxide is 0.0133g
as metal oxide (SnO2) per unit surface area (m2) of thinplate-like
metal substrate having a layer of an anti-corrosive treatment
in a non-aqueous system. Also the obtained colored interference
pigment having metallic luster with a reddish color having hue
angle (h) of 32.52 has the specific surface area of 29.80 m2/g.
SEM observation confirms the existence of high dense and
homogeneous coated layer of hydrated iron (III) oxide. The amount
of hydrated iron (III) oxide is about 0.76 g as Fe2O3 per unit
area (m2) of thin plate-like metal substrate having a layer of
an anti-corrosive treatment in a non-aqueous system.
Fig. 1 shows a comparison of SEM observation of
Fe2O3/SnO2/ [SiO2/Al (P) ] obtained in Example 1 and
Fe2O3/ [SiO2/Al (P) ] obtained in Comparative Example 1.
Fig. 2 shows a comparison of cross section by SEM
observation of Fe2O3/SnO2/ [SiO2/Al (P) ] obtained in Example 1

and Fe2O3/[SiO2/Al(P)] obtained in Comparative Example 1.
Fig. 3 shows a comparison of color measurements of
Fe2O3/SnO2/ [SiO2/Al(P)] obtained in Example 1 and Fe2O3/[SiO2/Al
(P)] obtained in Comparative Example 1 by Goniospectrophotometer
under different values of incident angle and observation angle.
A Murakami Goniospectrometer GC MS-3 is used. The observation
angle (R) is measured from 0° to 75° in steps of 5°. The incident
angle (I) is indicated in the figure.
[0046]
Hereafter specific examples for the use will be shown.
(Use example 1) Use examples for paint
Paint based on pearlescent pigments:

100 weight parts of Composition A are mixed with 20 weight
parts of Compositions, the resulting mixture is diluted to obtain
a viscosity (12 to 15 seconds with Ford Cup #4) suitable for
spray-coating with Composition C, and is spray-coated to form
a basecoat layer.
[0047]
Clear paint:
Acrydic 44-179 14 weight parts

This composition is coated on the above pearlescent base
coating, dried at 40 °C for 30 minutes, air-dried at room
temperature and baked (at 130 °C for 30 minutes) . The obtained
paint filmexhibits the interference colorhavingmetallic luster
with brilliant reddish color having high chromaticity.
[0048]
(Use example 2)
Use example for plastic:

These components are dry-blended and formed by injection
molding.
The molding containing a sample of example 1 exhibits the
interference color havingmetallic luster withbrilliant reddish
color.
[0049]
(Use example 3)
Use example for ink:
CCST medium (nitrocellulose resin) 10 weight parts
Sample of example 1 8 weight parts
The solvent NC 102 is added to the ink composition blended
from the above components, and ink with a viscosity of 2 0 seconds
with Zahn Cup No. 3 is prepared. Prints obtained with this ink
containing a sample of example 1 exhibits the interference color
having metallic luster with brilliant reddish color.
[0050]

(Use example 4)
Use example for cosmetics
Use example for compact powder:

[0051]
Formulation for foundation:

[Industrial Applicability]
[0052]
The colored interference pigment having metallic luster
of the present invention is one in which thin platelet-like metal
substrate having a layer of an anti-corrosive treatment in a
non-aqueous system is coated with an intermediate binder layer
thereon to improve the adhesion and denseness of the hydrated
iron oxide coated layer formed further outside thereof so that
the interference coloredpigment having metallic luster achieves
a reddish color with high luster and high coloration. Therefore,

it can be used in paints, inks, plastics, cosmetics, and others
which exhibit a reddish color.

WE CLAIM;
1. Colored interference pigments having metallic luster comprising, on the
surface of a thin platelet-like metal substrate as herein described a layer of an
anti-corrosive treatment such as herein described in a non-aqueous system, and,
thereon,
(1) an intermediate binder layer comprising hydrated tin oxide (first
layer); and thereon;
(2) a hydrated iron oxide layer (second layer),
the layer of an anti-corrosive treatment in a non-aqueous system being hydrated
metal oxide layer obtained from the following steps: Treating the surface of the
thin plate let-like metal substrate with phosphoric acids compounds and/or boric
acids compounds, followed by coating one or more hydrated metal oxide layers
of one or more metals selected from the group consisting of silicon, aluminum,
zirconium and titanium by the sol-gel method.
2. Colored interference pigments having metallic luster as claimed in claim 2,
wherein the metals of the hydrated metal oxide in said hydrated metal oxide
layer are silicon and/or aluminum.
3. Colored interference pigments having metallic luster as claimed in claim 2
wherein the metal of the hydrated metal oxide in said hydrated metal oxide layer
is silicon.
4. Colored interference pigments having metallic luster as claimed in any one of
claims 1 to 3, wherein said intermediate binder layer (the first layer) is a layer
comprising hydrated tin oxide obtained by the hydrolysis of a tin salt.

5. Colored interference pigments having metallic luster as claimed in any one of
claims 1 to 4 wherein the amount of hydrated tin oxide in the intermediate
binder layer ( the first layer)is not less than the amount which is necessary to
form a monolayer of hydrated tin oxide on the thin platelet-like metal substrate
having a layer of an anti-corrosive treatment in a non-aqueous system.
6. Colored interference pigments having metallic luster as claimed in any one of
claims 1 to 5, wherein the amount of hydrated tin oxide in the intermediate
binder layer (the first layer) is 0.0008g to 0.3g as metal oxide (SnO2) per unit
surface area (m2) of the thin platelet-like metal substrate having a layer of an
anti-corrosive treatment in a non-aqueous system.

7. Colored interference pigments having metallic luster as claimed in any one
of claims 1 to 6, wherein the amount of hydrated iron oxide in the hydrated iron
oxide coated layer (the second layer) is 0.01g to 1.0g as metal oxide (Fe2O3) per
unit surface area (m2) of the thin platelet-like metal substrate having a layer of
an anti-corrosive treatment in a non-aqueous system.
8. Method for preparing colored interference pigments having metallic luster,
comprising the folbwing steps:
-Dispersing/suspending thin platelet-like metal substrate particles
having a layer of an anti-corrosive treatment in a non-aqueous system in water,

- Adding simultaneously an aqueous solution of a tin salt and a basic aqueous
solution to the dispersion/suspension while keeping the pH value constant and
forming a first layer of a hydrated tin oxide ( an intermediate binder layer) on
the surface of said thin platelet-like metal substrate having a layer of an anti-
corrosive treatment in a non-aqueous system;and further
- Adding simultaneously an aqueous solution of an iron (III) salt and a basic
aqueous solution white keeping the pH value constant and forming a hydrated
iron oxide layer (the second layer).
9. A composition of resin/oil and pigment comprising a resin component,
and/or an oil component, and the colored interference pigments having metallic
luster as claimed in any one of claims 1 to 7.
10. Composition of resin/oil and pigment as claimed in claim 9, comprising
additively further pigments.

"COLORED INTERFERENCE PIGMENTS, A
METHOD FOR PREPARING THE SAME"
Colored interference pigments having metallic luster comprising, on the surface
of a thin platelet-like metal substrate a layer of an anti-corrosive treatment in a
non-aqueous system, and, thereon an intermediate binder layer comprising
hydrated tin oxide (first layer); and thereon, a hydrated iron oxide layer (second
layer), exhibiting a reddish color and improved adhesion and denseness of the
hydrated iron oxide layer, a process for producing same and their use.